The present invention relates to a coke oven battery. More specifically, this machine relates to such a battery having a control system using radio signals.
A coke oven battery has a plurality of coke ovens with an overhead coal bin for feeding coal into a series of hoppers of the coal charging cars (sometimes called larry cars). The coal charging cars, hereafter referred to as charging cars, in turn deposit coal in the coke ovens. The coal is turned into coke by application of high heat over an extended period of time. After the coal is turned into coke, a door machine opens a door on one side of the coke oven and has guide and hood functions to respectively guide coke into a quench car and capture emissions from the coke exiting the coke oven. Importantly, a pusher is on the side of the coke oven opposite the door machine and functions to push the coke out from the coke oven and into the quench car by way of the guide portion of the door machine. The pusher must not begin pushing until the door machine is properly positioned and has opened the door on the coke oven and performed related functions and the quench car is properly positioned with a positive closure of the bed gate.
The charging cars, door machines, pushers, and quench cars move along the series of coke ovens making up a coke battery. To avoid problems, it is necessary to coordinate the operations of these and possibly other machines which are used in the system.
Among prior patents which have shown various control arrangements for coke oven batteries are the following:
______________________________________ Inventor Patent No. ______________________________________ Teschner et al 4,190,498 Ikeda et al 4,674,054 Omae et al 5,314,168 Omae et al 5,253,846 Helm 3,618,794 Emark, Jr. 4,072,885 Richter et al 4,194,686 Krause et al 4,617,638 Aoki et al 5,155,681 ______________________________________
Teschner has coke oven battery machinery position control by radio.
The Ikeda patent shows the use of inductive radio (IR) lines to control pusher machines, charging cars, and other mechanisms in a coke oven. The IR lines are distributed along the paths of the various moving machines. A main controller such as a computer coordinates operations of the mechanisms.
The two Omae patents provide IR for computer control of a quenching car and/or a bucket car.
Helm discloses a coke oven control system using transmitters and receivers (detectors) for gamma rays.
The Emark and Richter patents teach that one can use wireless or cable control signals for coke transfer hot cars and similar machines.
Krause shows temperature sensing using computers and radio in a coke oven.
Aoki has an antenna for providing stop control in a coke oven mechanism.
Although the above and other systems have been generally useful, they have been subject to one or more of several disadvantages.
Generally, such systems have had reliability problems. Specifically, a coke oven battery is a very harsh environment due to heat, dust, gases, movement of large metal structures, and high electromagnetic noise. The environmental factors may quickly degrade various types of control systems and/or prevent reliable operation even when the system is new. For example, stray electromagnetic noise and metal structures (moving and stationary) may cause severe interference with those control systems operating by radio. Indeed, communication of control or data signals between a main controller and a machine may become impossible if the path between them is blocked by a metal machine.
In order to minimize problems from electromagnetic noise and metal structures, various of the radio control arrangements may use inductive radio (IR) communication. Such communication may improve reliability, but it disadvantageously requires one to put a radio inductive link along all or much of a machine's travel path. For example, a charging car having such a system would require a radio inductive link extending adjacent to a corresponding link in the charging car and having a length equal to the travel range of the charging car in order to establish communications all along the travel path of the charging car. Such a radio inductive link may have problems if made too long. Moreover, it is difficult and expensive to have such a radio link built in along the travel path of the machine. To the extent that one limits the inductive links to specific locations along the travel path, this means that the machine such as a charging car often can communicate with the main controller (also called land based since it doesn't move) only at certain locations along its travel path.
Regardless of the type of control system, very high reliability is becoming increasingly important in light of possible excess air pollution and associated heavy government fines. That is, a single malfunction out of 100,000 communications may seem like a high degree of reliability, but may still not be sufficient to avoid problems with air pollution, production losses, damage to equipment, etc.
Those systems which use radio communications may further encounter problems if a mobile radio on a delivery truck or other vehicle starts transmitting while close to the plant. This may be sufficient to knock out communications and, thus, control of the system.
A further problem with many coke battery control systems is that they don't respond well to temporary problems. That is, a momentary failure of communication may cause the system to shut down or otherwise take drastic action instead of more simple remedial action.